OUR MODERN LIFESTYLE has been blamed for many ills, including stress, depression and heart disease. And now it seems that the pursuit of greater cleanliness could be making us sick, too. For the latest modern ill is “chemical sensitivity” — a reaction to the man-made chemicals founds in products such as detergents, air fresheners and household pest killers.

The charity Allergy UK believes that more and more people are affected by chemical sensitivity. The charity’s helpline — set up six months ago — receives more than 200 calls a week, while a questionnaire sent to 60,000 people with allergies showed that 67 per cent had a reaction to chemicals.

Ten years ago Professor Nicholas Ashford, of the Massachusetts Institute of Technology, and Professor Claudia Miller, of the University of Texas, coined the term Toxicant-Induced Loss of Tolerance (Tilt) to describe chemical sensitivity. They found that Tilt diseases occur after exposure to a single large dose or many repeated smaller doses of a chemical, which is followed by increased sensitivity to small amounts of a variety of everyday chemicals.

The symptoms vary, says John Collard, a clinical nurse at the Airedale Allergy Centre in Keighley, West Yorkshire. They can include a runny nose, headaches, fatigue, skin conditions, asthma, vomiting and diarrhoea. In rare cases sufferers can experience anaphylactic shock, an extreme allergic reaction in which the immune system overreacts, leading to swelling, difficulty in breathing and unconsciousness.

Collard, who has spent nearly 20 years working with chemically sensitive patients, says that those who come into contact with chemicals regularly — eg, painters, hairdressers and carpet fitters — seem to be at the greatest risk.

Dr Michael Radcliffe, associate specialist in clinical allergy at the Royal Free Hospital, Hampstead, North London, and visiting clinical research fellow at the University of Southampton, says that more research is needed because doctors don’t know which body mechanism causes the symptoms.

When a patient’s history is traced, the symptoms are often found to have started after a large exposure to a chemical, such as during renovation work in the home when glues and solvents might be used, or by repeated smaller doses of a chemical, often at work.

“Something is going on that involves the endocrine system, the nervous system and the immune system,” Radcliffe says. “This is what we see in patients, and we know from classical toxicology that these systems can be affected by poisoning. But while we know that poisoning occurs from large amounts, what about repeated exposure to small amounts?” One theory is that chemically sensitive people cannot excrete chemicals effectively, and that these build up in the body. Another theory is that many of the products which trigger reactions, such as perfumes, contain volatile chemicals that are inhaled, going directly to the limbic system of the brain, where nerve impulses are triggered (with large, or repeated, exposure making the nerve endings sensitive).

However, the mainstream medical profession is sceptical, and doctors often put the symptoms down to psychosomatic causes. Dr Pamela Ewan, the president of the British Society for Allergy and Clinical Immunology, says it is possible for people to suffer from allergies to certain chemicals, but that the label “multiple chemical sensitivity” (as Tilt is known in the UK) is much too vague and leads to confusion.

“It is not a recognised disorder, and there is no agreed set of symptoms,” Ewan says. “It is much too broad a tag. There is a whole mixed problem here that needs to be sorted. Sufferers need to be seen by an allergist if the symptoms seem to be in that category, and if that is not appropriate, they need to be referred to other specialists.”

But Dr Honor Anthony, the president of the British Society for Allergy, Environmental and Nutritional Medicine, says that because sufferers often have a multitude of symptoms, they are referred to a variety of consultants, who don’t address the underlying cause.

“The evidence that symptoms are caused by allergic responses is compelling,” she says. “But if a patient has a multiplicity of symptoms, it tends to get equated with psychogenic causes, when I don’t believe there is any evidence that this is so.”

Radcliffe says: “Some patients will have psychosomatic mechanisms going on. Odour is a potent stimulus. But the real question is not whether it is psychological or physical in each case, but what proportion is and what is not.”

Until four years ago, patients who were affected severely might have been admitted to the Airedale Allergy Centre, which had an environmentally controlled inpatient facility where sufferers could be tested to find out exactly what was causing the problem. But the ten-bed unit, which treated about 160 patients a year, closed after changes in NHS funding, and although chemically sensitive patients are seen as outpatients, most have to pay privately.

“There is an urgent need for this kind of facility. We need to pin down what is causing the symptoms,” says Anthony, who used to work at the unit.

Currently, those with chemical sensitivity have to rely on their GPs to refer them to the appropriate consultant, depending on the symptoms.

However, there is only a handful of doctors with experience in the field of chemical sensitivity, and most are in private practice. Allergy UK says that its helpline can point people towards “sympathetic” doctors.

But as far as treatment goes, there is no cure. As Radcliffe explains: “We can only teach people how to manage their symptoms and lead a normal life. But the climate is beginning to shift, with many doctors now acknowledging that there might be a problem. I believe that eventually this is going to have as big an impact on the way we do things as the Germ Theory did. But first we need to recognise that something is going on, and look at how people are getting sick.”

Allergy UK Chemical Sensitivity helpline:
020-8303 8525

www.allergyfoundation.com

Explore Health

• Expert Advice

• Health Features

• Mental Health

• Alternative Medicine

• Child Health

• Health Club